There are three ways to defrost (thaw) frozen salmon fillets (link to my favorite frozen salmon supplier). The trick is that the slower you thaw your fillets, the better they will be due to the way cells act as they thaw.
Thawing salmon overnight in the refrigerator is the best method for preserving the quality of your fish, but if you are pressed for time, a few minutes in a water bath will thaw salmon without damaging it.
Thawing Salmon in the Fridge
This is the hands-down the best way to thaw salmon, provided you have the time and presence of mind to pull it out and put it in the fridge the night before you need it. All you need to do is pull your fish out of the freezer, put it in a dish and slide it into the fridge. You definitely want to have it in a tray because as it thaws, there may be a small hole in the bag and your fridge will wind up with fish-water in it, which is no fun to clean up.
Chunks of salmon up to a pound should thaw in about 12 hours, but allow up to 24 hours for sections larger than a pound.
Defrosting Salmon In a Water Bath
This is honestly the method I use the most for thawing out salmon fillets. Put a large bowl in the sink, fill with water and add your salmon fillets. If for some reason they aren’t in plastic bags, put them in one. Then just barely trickle cold water into your bowl.
If you are working with fillets, it will take about 30 minutes for them to thaw, which is perfect to either prep your sides or else pour a glass of wine and relax for a few minutes before you start cooking. You will know that it is thawed when you can squeeze the middle of the fish and it is slightly soft and flexible.
The Fastest Way to Thaw Salmon Fillets
Hands down, the fastest way to thaw salmon fillets is to microwave them. The only risk is that you may affect the texture and flavor or partially cook your fish in the process.
If your microwave has a setting for defrost, and enter the approximate weight of your fillets. You will want to rotate and flip often to thaw them evenly. Be sure to stop when your fish is barely thawed and cold but still flexible. Do not overcook your salmon. Using this method, you can expect to need 6 to 8 minutes per pound of fish.
Skip Thawing and Cook Your Frozen Salmon
If you really don’t want to fuss with it, you can just skip the thawing and often times just cook your frozen salmon fillets. You can bake, grill or pan-fry salmon fillets that are frozen, it just means a longer cooking time.
Really Serious About Thawing Salmon?
In researching articles, I come across some interesting things. In this case, it is a piece of commercial kitchen equipment that will perfectly defrost your salmon (or anything else) in minutes. They don’t let on what happens inside their magic box, but it perfectly thaws your salmon without damaging it. So if you have a few thousand dollars and some kitchen space to spare, you might want to pick one up from Ice-Off.